This study will assess the pharmacokinetics of BMS-204352 in patients with stable cerebrovascular disease. It would also be important to determine whether BMS-204352 causes regional perfusion deficits in patients with stable cerebrovascular disease, as has been found for dipyridamole or acetazolamide. The present study will assess the effects of BMS-204352 on regional cerebral blood flow using positron emission tomography (PET) and MRI methodology.